Monoterpene biosynthesis in lemon (Citrus limon) cDNA isolation and functional analysis of four monoterpene synthases

Joost Lücker, Mazen K. El Tamer, Wilfried Schwab, Francel W.A. Verstappen, Linus H.W. Van Der Plas, Harro J. Bouwmeester, Harrie A. Verhoeven

Research output: Contribution to journalArticlepeer-review

161 Scopus citations


Citrus limon possesses a high content and large variety of monoterpenoids, especially in the glands of the fruit flavedo. The genes responsible for the production of these monoterpenes have never been isolated. By applying a random sequencing approach to a cDNA library from mRNA isolated from the peel of young developing fruit, four monoterpene synthase cDNAs were isolated that appear to be new members of the previously reported tpsb family. Based on sequence homology and phylogenetic analysis, these sequences cluster in two separate groups. All four cDNAs could be functionally expressed in Escherichia coli after removal of their plastid targeting signals. The mainproducts of the enzymes in assays with geranyl diphosphate as substrate were (+)-limonene (two cDNAs) (-)-β-pinene and γ-terpinene. All enzymes exhibited a pH optimum around 7; addition of Mn2+ as bivalent metal ion cofactor resulted in higher activity than Mg2+, with an optimum concentration of 0.6 mM. Km values ranged from 0.7 to 3.1 μM. The four enzymes account for the production of 10 out of the 17 monoterpene skeletons commonly observed in lemon peel oil, corresponding to more than 90% of the main components present.

Original languageEnglish
Pages (from-to)3160-3171
Number of pages12
JournalEuropean Journal of Biochemistry
Issue number13
StatePublished - 2002
Externally publishedYes


  • (+)-limonene synthase
  • (-)-β-pinene synthase
  • Citrus limon
  • Functional expression
  • γ-terpinene synthase


Dive into the research topics of 'Monoterpene biosynthesis in lemon (Citrus limon) cDNA isolation and functional analysis of four monoterpene synthases'. Together they form a unique fingerprint.

Cite this